A Successful Case of Conversion Therapy after Chemotherapy for Advanced Rectal Cancer with Inguinal Lymph Node Metastasis

CASE: A70-year-old man was diagnosed with lower rectal cancer with right inguinal lymph node metastasis. Surgical resection was not suitable for this patient. Chemotherapy(IRIS plus bevacizumab followed by XELOX plus bevacizumab)was administered for 16 months. After the chemotherapy, the rectal tumor and lymph node swelling were significantly reduced and distant metastasis was not observed on CT scans. Therefore, the tumor was considered to be resectable and abdominoperineal resection of the rectum with lymph node dissection was performed. On histopathological examination, cancer cells partially remained in the rectal tumor and lateral lymph nodes, although there were no cancer cells in the inguinal lymph nodes. The patient is alive without recurrence a year later. In cases with a good response to chemotherapy, conversion therapy may become an important therapeutic option.